Device For the Positioning of Optical Elements With Retractable Stop

A device for the positioning of optical elements with retractable stop enabling accurate positioning of an optical element selected among a plurality of optical elements, including:

• a stand (1);
• a turret (2) fitted with an element holder (3) carrying said plurality of optical elements, and with a disc (4) integral with the element holder (3), said disc (4) being a ratchet wheel having a peripheral surface (5) fitted with a plurality of blocking means (6), each blocking means (6) corresponding to an optical element,
• a motor (7) capable of driving said disc (4) in rotation relative to said stand (1) around a first axis in a so-called forward direction and in a reverse direction;
• and,
• a crash stop (9) bearing against the peripheral surface of the disc (5) and capable of retracting by moving around a second axis when actuating said motor (7) for driving the disc (4) in the forward direction, said crash stop (9) being capable of engaging with a blocking means (6) so as to block said disc (4) in position when actuating the motor (7) for driving the disc (4) in the opposite direction,
• characterised in that the crash stop (9) contains an anti-friction element (13) in contact with the peripheral surface (5) of the ratchet wheel so that the retractable stop (9) moves according to the contour of the peripheral surface (5) of the ratchet wheel without any friction.